Comparison of gluteus maximus, biceps femoris, and multifidus muscle activity of prone hip extension with and without reciprocal inhibition in healthy individuals

BackgroundProne hip extension (PHE) is commonly used in rehabilitation to selectively activate the gluteus maximus (GM) and enhance lumbopelvic stability. However, excessive activity of the biceps femoris (BF) during PHE often interferes with efficient GM recruitment. The application of reciprocal inhibition (RI) might be suggested as a potential solution.ObjectiveThis study aimed to investigate the effects of applying RI with and without non-elastic band resistance during PHE with 90° knee flexion on the muscle activity and activity ratio of the GM, BF, and multifidus (MF).MethodsTwenty healthy male individuals performed PHE exercises under two conditions: with and without RI using a non-elastic band. Surface electromyography (sEMG) was used to assess the activity levels of GM, BF, and MF, and to calculate the GM/BF and MF/BF activity ratios. Paired t-tests were conducted for statistical analysis.ResultsCompared with the condition without RI, GM activity increased from 32 to 37.47%MVIC (p = 0.02), and the GM/BF ratio increased from 1.19 to 2.13 (p = 0.001), whereas BF activity decreased from 29.26 to 19.87%MVIC (p = 0.001). No significant difference was observed in MF activity between conditions (Rt_MF: p = 0.86, Lt_MF: p = 0.5).ConclusionApplying RI during PHE effectively enhances selective activation of the GM while reducing compensatory BF activity. These findings suggest that RI-based exercise can be recommended as an effective strategy for target muscle activity in clinical settings.